Two phase ball expansion valve for heat pump

Abstract

A device for expansion of coolant having a housing with a flow channel. A ball-shaped valve element arranged to be integrated inside the housing. The valve element is mounted so that it can turn about an axis of rotation and is configured with a through channel. The through channel of the valve element is configured with an entry opening and an exit opening and arranged so that the flow cross section of the through channel decreases from the entry opening to the exit opening in the direction of flow of the coolant. At the exit of the through channel the least flow cross section is formed.

Claims

1. A device for expansion of a coolant, the device comprising: a housing with a flow channel formed therein, the flow channel including a first segment having a first cross-sectional flow area and a second segment having a second cross-sectional flow area, wherein the first cross-sectional flow area is substantially equal to the second cross-sectional flow area; and a ball-shaped valve element disposed in the housing intermediate the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel and configured to rotate about an axis of rotation, the valve element having a through channel formed therein configured for selective fluid communication with the flow channel of the housing, the through channel including an entry opening having a third cross-sectional flow area and an exit opening having a fourth cross-sectional flow area smaller than the third cross-sectional flow area, wherein the third cross-sectional flow area of the entry opening is larger than each of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel, and wherein the fourth cross-sectional flow area of the exit opening is smaller than each of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel, wherein the valve element is continuously adjustable in intermediate positions between a first fully opened end position, a fully closed position, and a second fully opened end position, and wherein the valve element is turned by 180° between the first fully opened end position and the second fully opened end position, wherein a first overlap present between the third cross-sectional flow area of the entry opening and one of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel remains constant when the valve element is rotated through a first range of rotational positions and wherein a second overlap present between the fourth cross-sectional flow area of the exit opening and an other of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel remains constant when the valve element is rotated through the first range of rotational positions, and wherein the first overlap and the second overlap establish the selective fluid communication between the through channel of the valve element and the flow channel of the housing.

2. The device according to claim 1, wherein the through channel of the valve element has a substantially conical shape.

3. The device according to claim 1, wherein the through channel of the valve element has a shape of a truncated cone.

4. The device according to claim 3, wherein the through channel of the valve element has the shape of a straight truncated cone.

5. The device according to claim 1, wherein the through channel is bounded by a surface of rotation which is formed by rotation of a line about an axis of symmetry to create a substantially circular flow cross section which reduces substantially uniformly from the entry opening with a larger diameter than the exit opening.

6. The device according to claim 1, wherein a diameter of the entry opening of the through channel is larger than a diameter of the flow channel of the housing.

7. The device according to claim 1, wherein a diameter of the entry opening of the through channel substantially equal to a diameter of the flow channel of the housing.

8. The device according to claim 1, wherein a diameter of the exit opening of the through channel is smaller than a diameter of the flow channel of the housing.

9. The device according to claim 1, wherein a transition zone at the entry opening to the through channel of the valve element between a surface forming the through channel and an outer surface of the valve element is rounded.

10. The device according to claim 1, wherein a first 90° turn adjusts the valve element between the first fully opened end position and the fully closed position and wherein a second 90° turn adjusts the valve element between the second fully opened end position and the fully closed position.

11. The device according to claim 1, wherein the valve element is configured to receive a bidirectional flow of the coolant therethrough.

12. A device for expansion of a coolant, the device comprising: a housing with a flow channel formed therein, the flow channel including a first segment having a first cross-sectional flow area and a second segment having a second cross-sectional flow area, wherein the first cross-sectional flow area is substantially equal to the second cross-sectional flow area; and a ball-shaped valve element disposed in the housing intermediate the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel and configured to rotate about an axis of rotation, the valve element having a through channel formed therein configured for selective fluid communication with the flow channel of the housing, the through channel including an entry opening having a third cross-sectional flow area and an exit opening having a fourth cross-sectional flow area smaller than the third cross-sectional flow area, a diameter of the entry opening of the through channel larger than a diameter of each of the first segment and the second segment of the flow channel of the housing and a diameter of the exit opening of the through channel smaller than the diameter of each of the first segment and the second segment of the flow channel of the housing, wherein the valve element is continuously adjustable in intermediate positions between a first fully opened end position, a fully closed position, and a second fully opened end position, and wherein the valve element is turned by 180° between the first fully opened end position and the second fully opened end position, wherein a first overlap present between the third cross-sectional flow area of the entry opening and one of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel remains constant when the valve element is rotated through a first range of rotational positions and wherein a second overlap present between the fourth cross-sectional flow area of the exit opening and an other of the first cross-sectional flow area of the first segment of the flow channel and the second cross-sectional flow area of the second segment of the flow channel remains constant when the valve element is rotated through the first range of rotational positions, wherein the first overlap and the second overlap establish the selective fluid communication between the through channel of the valve element and the flow channel of the housing.

13. The device according to claim 12, wherein the through channel of the valve element has a substantially conical shape.

14. The device according to claim 12, wherein a transition zone at the entry opening to the through channel of the valve element between a surface forming the through channel and an outer surface of the valve element is rounded.

15. The device according to claim 12, wherein a first 90° turn adjusts the valve element between the first fully opened end position and the fully closed position and wherein a second 90° turn adjusts the valve element between the second fully opened end position and the fully closed position.

16. The device according to claim 12, wherein the valve element is configured to receive a bidirectional flow of the coolant therethrough.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details, features, and benefits of the invention will emerge from the following specification of sample embodiments making reference to the corresponding drawings. There are shown:

(2) FIG. 1: cross section of a ball valve according to the prior art;

(3) FIG. 2A to 2C: device with modified valve element in “fully opened” position;

(4) FIG. 3: valve element from FIG. 2A to 2C in perspective view,

(5) FIG. 4A: switch position of the valve element from FIG. 2A to 2C with flow direction to the right,

(6) FIG. 4B: switch position of the valve element from FIG. 2A to 2C with flow direction to the left, and

(7) FIG. 5A and 5B: device with modified valve element in “closed” position.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(8) The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.

(9) FIGS. 2A to 2C show the device 1 for expansion of coolant, especially for a coolant circuit of an air conditioning system of a motor vehicle, each time in the “fully opened” position.

(10) The device 1, configured as a ball valve, essentially comprises a servo drive (not shown), a shaft (not shown) as the connection between the servo drive and a ball-shaped valve element 2 with a through channel 6 as the flow channel for the coolant, as well as a housing 3 as a support for the valve element 2. The valve element 2 is mounted so it can turn about an axis of rotation 7. The housing 3 is fashioned with a flow channel 4.

(11) Consequently, the device 1 is a so-called expansion ball valve.

(12) In the at least partly opened position of the valve element 2, the coolant flows in the flow direction 5 from right to left through the device 1. In the positions of the valve element 2 “fully opened” as shown in FIG. 2A to 2C, the maximum mass flow of coolant flows through the device 1. An expansion cross section 10 is completely clear and not covered by the housing 3.

(13) Even deviating from the horizontal position of FIG. 2A, the device 1 remains within a “fully opened” angle α, while the valve element 2 per FIG. 2B and 2C can be moved in both directions of turning by the angle α/2 each time.

(14) The ball-shaped valve element 2, which has been modified from the prior art, is fashioned with the through channel 6 as a conical hole. Traditional ball valves 11 per FIG. 1, on the other hand, have valve elements 2 with cylindrical through channels 16. The conical shape of the through channel 6 also emerges from FIG. 3, which shows the valve element 2 in a perspective view.

(15) The flow channel 6 bounded by a surface of rotation 8 has the shape of a truncated cone. The surface of rotation 8 is formed here by rotation of a straight line about the axis of symmetry 9. The round flow cross section of the through channel 6 is reduced uniformly by means of the conical shape between two nominal widths, that is, from the entry opening with a cross section with larger diameter to the exit opening with a cross section with smaller diameter. The round flow cross section with the smaller diameter corresponds to the expansion cross section 10 in the positions “fully opened” of the valve element 2 per FIG. 2A to 2C.

(16) The coolant flows in the flow direction 5 into the device 1, and it is taken through the through channel 4 and the housing 3 to the valve element 2. The transition from the flow channel 4 of the housing 3 to the through channel 6 of the valve element 2 is configured such that swirling of the coolant is minimized. Advantageously, the entry opening to the conical through channel 6 is rounded for streamlining at the transition from the surface of rotation 8 to the outer surface of the valve element 2. The entry opening of the through channel 6 has a larger or at least an equally large diameter to the flow channel 4.

(17) The coolant upon emerging from the valve element 2 is expanded into the flow channel 4, since the exit opening being the expansion cross section 10 has a much smaller diameter than the adjoining flow channel 4 in the direction of flow 5 of the coolant.

(18) The pressure built up by the coolant upon flowing through the ball-shaped valve element 2 with narrowing flow cross section presses the valve element 2 against the housing 3 so that the tightness of the valve is assured.

(19) The valve element 2 mounted with ability to turn about the axis of rotation 7 can be adjusted continuously in intermediate positions between the three end positions of “fully opened”, “closed” and “fully opened”. Between the end positions of “fully opened” and “closed” the valve element 2 is turned each time through 90°, while the valve element 2 within each end position can be turned in a particular angle range and has the condition of “fully opened” or “closed”.

(20) FIG. 4A shows the valve element 2 of FIG. 2 in an intermediate position with flow direction 5 of the coolant from left to right. The valve element 2 is moved counterclockwise about the axis of rotation 7, as compared to the position from FIG. 2. During the movement, the housing 3 increasingly covers the exit opening of the through channel 6, so that the expansion cross section 10′, as the smallest flow cross section through the device 1, is decreased as the movement continues. The mass flow of coolant becomes smaller. Since the expansion cross section 10′ is configured as the only site with the smallest flow cross section, there is no risk of an indefinable expansion and thus evaporation of the coolant in another place, which would block the flow cross section and hinder a correct regulation of the mass flow of coolant.

(21) A further turning of the valve element 2 results in the wall of the valve element 2 completely blocking the flow channel 4 of the housing 3, as can be seen in FIG. 5A and 5B. In the “closed” middle position of the valve element 2 (not shown), the axis of symmetry 9 is perpendicular in relation to one of the “fully opened” end positions.

(22) Even in a position deviating from the perpendicular position, the device 1 remains within a “closed” angle β, while the valve element 2 per FIG. 5A and 5B can be moved in both directions of turning by the angle β/2 each time.

(23) FIG. 4B shows the valve element 2 from FIG. 2 in an intermediate position with the flow direction 5′ of coolant from right to left. The valve element 2 is further moved counterclockwise about the axis of rotation 7 as compared to the position from FIG. 4A. During the movement, the exit opening of the through channel 6 is increasingly opened up, so that the expansion cross section 10″, as the smallest flow cross section through the device 1, is increased as the movement continues. The mass flow of coolant becomes larger. Since the expansion cross section 10″ is once again configured as the only site with the smallest flow cross section, there is likewise no risk of an indefinable expansion and thus evaporation of the coolant in another place, so that a correct regulation of the mass flow of coolant is possible.

(24) After a turning by a total of 180° to the “fully opened” end position of FIG. 2, the valve element 2 is back at the “fully opened” end position, and coolant flows through the device 1 in the opposite flow direction.

(25) Thus, the device 1 configured as a ball valve can receive a bidirectional flow, or flow from either side, and it enables the correct regulation of the mass flow of coolant by configuring only a single expansion cross section 10′, 10″ as the through opening between the housing 3 and the valve element 2.

(26) The device 1 is furthermore able to operate with an actuator as the servo element in a regulatory circuit, that is, an element which transforms the input variable into a different output variable, which the valve element 2 has to move by an angle of rotation of at most 180°. The movement of the valve element 2 furthermore includes the “closed” position, so that the device 1 also performs the function of a shutoff valve.

(27) While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the disclosure, which is further described in the following appended claims.

LIST OF REFERENCE NUMBERS

(28) 1 device 2 ball-shaped valve element 3 housing 4 flow channel of housing 3 5, 5′ coolant direction of flow 6 through channel 7 axis of rotation 8 surface of rotation 9 axis of symmetry 10, 10′, 10″ expansion cross section 11 ball valve 12 ball-shaped valve element 13 housing, support element 14 flow channel of housing 13 15 direction of flow 16 through channel 17 axis of rotation 18a, 18b opening, expansion cross section α angle for turning within “fully opened” position β angle for turning within “closed” position